Nearby-fluids equilibria.: II.: Zonal flows in a high-β, self-organized plasma experiment

The field and flow structure observed in a high-beta field reversed configuration (FRC) produced in the translation, confinement, and sustainment (TCS) experiment are modeled using the newly developed nearby-fluids equilibrium model. These results are the first evidence that experimental FRCs have complex flows, that is nonrigid rotational flow and poloidal flow, both with maximum speeds nearly half the Alfven speed. The interpretive approach is an innovative backwards method using the nearby-fluids platform for two-fluid equilibria. The most remarkable outcome is the prediction of a poloidal flow structure with significant zonal features. The poloidal flow has never been directly measured in FRCs; thus this discovery results from applying the flowing equilibrium model as an interpretive tool. The poloidal flows explain the unusual toroidal field structure observed in TCS. Zonal features in the rotational flow are also inferred from the unfolding of chord-integrated measurements. The results also indicated that a broad core of the FRC is very close to a minimum energy state. (c) 2006 American Institute of Physics.